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4.2.2.4 app.cpp

Here is our main application source file, the bulk of changes for this tutorial occur in this file. Before we can get into the details of creating a quest the following final set up must be performed in the Application () method of the main app.

 
if (!pl->LoadPropertyClassFactory ("cel.pcfactory.logic.quest"))
  return false;

//myQuest
csRef<iCelEntity> quest = CreateQuest("myquest");
if (!quest) printf ("CreateQuest(""myquest"") Failed!\n");

This simply loads the quest factory, and calls, with rudimentary error handling, the create quest method detailed below.

 
csPtr<iCelEntity> MainApp::CreateQuest (const char* name)
{
  // The Quest Entity
  entity_quest = pl->CreateEntity (name, bl, "quest_behave",
    "pclogic.quest", "pctools.properties", CEL_PROPCLASS_END);

  csRef<iQuestManager> qm = csQueryRegistryOrLoad<iQuestManager> (object_reg,
    "cel.manager.quests");

  //-----------------------------------------------------------
  // Create 'testquest'.
  //-----------------------------------------------------------
  iQuestFactory* fact = qm->CreateQuestFactory ("testquest");
  if (!fact)
  {
    printf("Factory Create Failed");
    return 0;
  }

A Quest is an entity, and as such must be created with a call to the physical layer method CreateEntity (...).

The Quest Manager (variable qm above) is a critical component for the construction and setup of quests. For example, the first task of the quest manager is create a quest factory for the constuction of the example quest 'testquest'.

Quests are essentially Finite State Machines and as such they are made up by a number of states. Each state has responses that will occur when an assigned trigger fires if the Quest is currently in that state. Each response has one trigger. When the trigger fires any rewards assigned to that response will execute. Each response can have multiple rewards.

As an example, below is the state definition of the initial state of the example quest. The first two method calls create the state, and its sole response. The remainder sets up the assigned trigger and various rewards.

 
// ---- init state ----
iQuestStateFactory* state_init = fact->CreateState ("init");
iQuestTriggerResponseFactory* init_response =
  state_init->CreateTriggerResponseFactory ();

qm->SetTimeoutTrigger (init_response, "10");
qm->AddDebugPrintReward (init_response, "\n\nWelcome To The Example Quest");

qm->AddDebugPrintReward (init_response, " -Initalising counter parameter");
iChangePropertyRewardFactory* rf_changeprop = qm->AddChangePropertyReward
  (init_response, name, "counter");
rf_changeprop->SetLongParameter ("0");

qm->AddDebugPrintReward (init_response, " -Clearing all walktut boxes");
qm->AddDestroyEntityReward (init_response, "box1");
qm->AddDestroyEntityReward (init_response, "box2");
qm->AddDestroyEntityReward (init_response, "box3");

qm->AddDebugPrintReward (init_response, " -Creating money box");
const celEntityTemplateParams tpl_params;
qm->AddCreateEntityReward (init_response, "BoxTemplate", "templateBox", tpl_params);

qm->AddDebugPrintReward (init_response, " -Entering 1st State\n");
qm->AddNewStateReward (init_response, name, "start");

The sole response in this example, is fired by a time out trigger. Once the timer reaches 10 seconds the welcome message is displayed and the game sets up. This state demonstrates a wide range of possible reward uses, from entity creation/deletion to parameter manipulation.

This state makes extensive use of convenience methods available in the quest manager to simplify the process of adding trigger and rewards to a response. At the time of writing all triggers and responses have a corresponding convenience method.

The final reward moves the quest into another state. Once in the next state the above response will not occur again. However, if we were to later return to this state the game would begin again. A simple practical exercise to test your understanding would be to implement a reset function on this small game, that would move back to this state after the winning or losing state is reached.

Below is the code for the next state, which is the main part of the game logic.

 
// ---- start state ----
iQuestStateFactory* state_start = fact->CreateState ("start");

iRewardType* type = qm->GetRewardType ("cel.rewards.debugprint");
csRef<iRewardFactory> rewfact = type->CreateRewardFactory ();
csRef<iDebugPrintRewardFactory> dbg_rewfact = scfQueryInterface<iDebugPrintRewardFactory> (rewfact);
dbg_rewfact->SetMessageParameter ("State Changed => The Game Has Begun");
state_start->AddInitRewardFactory (rewfact);

iQuestTriggerResponseFactory* start_response1 =
  state_start->CreateTriggerResponseFactory ();
qm->SetTimeoutTrigger (start_response1, "10");

qm->AddDebugPrintReward (start_response1, " -Money Box Self Destuct Sequence Has Begun\n");
csRef<iCelSequenceFactory> destruct_seq = fact->CreateSequence("sequence_destruct");
csRef<iSeqOpFactory> seqopfact = qm->GetSeqOpType("cel.seqops.debugprint")->CreateSeqOpFactory();
csRef<iDebugPrintSeqOpFactory> destruct_seqopfact =
  scfQueryInterface<iDebugPrintSeqOpFactory> (seqopfact);
destruct_seqopfact->SetMessageParameter("Self Destruct Progress : ");
destruct_seq->AddSeqOpFactory(seqopfact, "1000");
qm->AddSequenceReward(start_response1, name, "sequence_destruct", "10");

iQuestTriggerResponseFactory* start_response2 =
  state_start->CreateTriggerResponseFactory ();
qm->SetMeshSelectTrigger(start_response2, "templateBox");
qm->AddDebugPrintReward(start_response2, "You Picked Up The Money Box & Stopped The Self Destruct\n");
qm->AddNewStateReward (start_response2, name, "box_pickup");

iQuestTriggerResponseFactory* start_response3 =
  state_start->CreateTriggerResponseFactory ();
qm->SetSequenceFinishTrigger(start_response3, name, "sequence_destruct");
qm->AddDestroyEntityReward (start_response3, "templateBox");
qm->AddDebugPrintReward(start_response3, "SELF-DESTRUCT HAS OCCURRED\n");
qm->AddNewStateReward (start_response3, name, "box_explode");

This state starts slighlty different, with the construction of a reward without the use of the convenience methods. If you are using a new reward/trigger that does not have a corresponding convenience method, the factory must be created from the type and setup as here for the game start message.

The reward factory created, however, is not assigned to a standard response. Instead it is set as the on init reward factory. This means the game started message will display as the state is entered. A similar method is available for the addition of on exit rewards.

The following three responses in this code example are regular in state responses. The first starts the self destruct sequence of the money box. This sequence simply uses a debug message, but the sequence tool can also be used to create effects combining any seq ops. Current potential examples, include closing doors and changing light colors.

The second is triggered by the money box being picked up. The player can pick up the box by clicking on it, and the mesh select trigger will fire upon this occuring. The quest moves into the final state where on init it stops the self destruct sequence.

The final response is triggered if the sequence ends in its own time, this is then reported to the player and the quest is moved into a different final state. This response is not triggered when the sequence is finished by the player picking up the box because the quest has moved into a different state before the sequence finish reward is executed.

The two final states, denote success or failure in the game. If the player has picked up the box they will have moved into the box_pickup state where the counter is updated to show their success and the player informed. This makes use of the property manipulation reward and a trigger that fires upon a property change. This state also includes another example of the reward on init feature.

However, if the player has not picked up the box the bad_one will haunt them. That is it will be added to their inventory to symbolise hiding in their jacket. This shows the inventory reward that can add entities to a players inventory. This response also makes use of the message send reward and message received trigger to announce the players failure.

 
// ---- box_pickup state ----
iQuestStateFactory* state_box_pickup = fact->CreateState ("box_pickup");

type = qm->GetRewardType ("cel.rewards.sequencefinish");
csRef<iRewardFactory> seq_fin_rewfact = type->CreateRewardFactory ();
csRef<iSequenceFinishRewardFactory> explicit_seq_fin_rewfact =
  scfQueryInterface<iSequenceFinishRewardFactory> (seq_fin_rewfact);
explicit_seq_fin_rewfact->SetEntityParameter (name);
explicit_seq_fin_rewfact->SetSequenceParameter ("sequence_destruct");
state_box_pickup->AddInitRewardFactory(seq_fin_rewfact);

iQuestTriggerResponseFactory* box_pickup_response1 =
  state_box_pickup->CreateTriggerResponseFactory ();
qm->SetTimeoutTrigger (box_pickup_response1, "10");
rf_changeprop = qm->AddChangePropertyReward
  (box_pickup_response1, name, "counter");
rf_changeprop->SetLongParameter ("1");

iQuestTriggerResponseFactory* box_pickup_response2 =
  state_box_pickup->CreateTriggerResponseFactory ();
qm->SetPropertyChangeTrigger (box_pickup_response2, name, "counter", "1");
qm->AddDebugPrintReward(box_pickup_response2, "Counter Updated To Reflect Pickup => You Have Won");

// ---- box_explode state ----
iQuestStateFactory* state_box_explode = fact->CreateState ("box_explode");

iQuestTriggerResponseFactory* box_explode_response1 =
  state_box_explode->CreateTriggerResponseFactory ();
qm->SetTimeoutTrigger (box_explode_response1, "10");
qm->AddInventoryReward (box_explode_response1, "player", "badone");

iQuestTriggerResponseFactory* box_explode_response2 =
  state_box_explode->CreateTriggerResponseFactory ();
qm->SetInventoryTrigger(box_explode_response2, "player", "badone");
qm->AddDebugPrintReward(box_explode_response2, "Badone Hid In Your Cloak From The Explosion");

iQuestTriggerResponseFactory* box_explode_response3 =
  state_box_explode->CreateTriggerResponseFactory ();
qm->SetTimeoutTrigger (box_explode_response3, "50");
qm->AddMessageReward(box_explode_response3, "player", "You Lose");

iQuestTriggerResponseFactory* box_explode_response4 =
  state_box_explode->CreateTriggerResponseFactory ();
qm->SetMessageTrigger(box_explode_response4, "player", "You Lose");
qm->AddDebugPrintReward(box_explode_response4, "Message Trigger Fired => You Have Lost");

Finally, the quest must be created and started.

 
  csRef<iPcQuest> pcquest = CEL_QUERY_PROPCLASS_ENT (entity_quest, iPcQuest);
  celParams params;

  if (!pcquest->NewQuest ("testquest", params))
  {
    ReportError ("Error creating quest '%s'!", "testquest");
    return 0;
  }

  pcquest->GetQuest ()->SwitchState ("init");
  return csPtr<iCelEntity> (entity_quest);
}

The NewQuest method creates the quest, with error handling to report any error that occurs.

Any parameters used in the Quest must be stored in a celParams and passed to the NewQuest method. However, none were used in this tutorial

The Quest must then be switched to the initial state, from where it will begin execution.


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